Redundantly Actuated Parallel Mechanism of Ankle Rehabilitation
A 2-dof, redundantly actuated parallel mechanism is proposed for ankle rehabilitation. The mechanism has the advantage of mechanical and kinematic simplicity when compared to existing multi-degree of freedom parallel mechanism prototypes, while at the same time it is fully capable of carrying out the exercises required in ankle rehabilitation protocols. The proposed device allows plantar/dorsiflexion and inversion/eversion using an improved performance parallel mechanism which makes use of actuation redundancy to eliminate singularity and greatly improve the workspace dexterity. This assures smooth motion of the platform during clinical rehabilitation since the mechanism workspace does not contain singularities.
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| Fig. 1 Prototype of the ankle rehabilitation robot |
Watch the Robotic Ankle in action
In addition the requirements for high torque capacity and backdrivability are further satisfied with the employment of a customized cable-driven linear electric actuator that combines high force capacity with low friction and high backdrivability. The simplicity and compactness of the device together with its redundant characteristic, which allows simultaneous control of position and stiffness, will improve the quality of and increase the productivity of ankle physiotherapy delivered by the clinicians.
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| Transmission system for the linear actuator |
Patents
Linear actuator and rehabilitation device
Publications
- J. A. Saglia and J. S. Dai, Geometry and Kinematics Analysis of a Redundantly Actuated Parallel Mechanism for Rehabilitation, Proceedings of DETC'07, ASME 2006 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, September 4-7, 2007, Las Vegas, Nevada.
- J. Saglia, J.S. Dai and D.G. Caldwell, Geometry and Kinematic Analysis of a Redundantly Actuated Parallel Mechanism that Eliminates Singularity and Improves Dexterity, Transactions of the ASME: Journal of Mechanical Design, vol. 130, no. 12, page 124501_1-5, 2008.
- J. Saglia, N.G. Tsagarakis, J.S. Dai and D.G. Caldwell, Inverse Kinematics Based Control of a Redundantly Actuated Platform for Rehabilitation, Proceedings of the IMechE, Part I, Journal of Systems and Control Engineering, vol. 223, no. 1, pp. 53-70, 2009.
- J. Saglia, N.G. Tsagarakis, J.S. Dai and D.G. Caldwell, A High Performance 2-dof Over-Actuated Parallel Mechanism for Ankle Rehabilitation, Proceedings of the IEEE International Conference on Robotics and Automation, Kobe, Japan, May 12-17, 2009.
- J. Saglia, N.G. Tsagarakis, J.S. Dai and D.G. Caldwell, A High-performance Redundantly Actuated Parallel Mechanism for Ankle Rehabilitation, International Journal of Robotics Research, Special Issue on Medical Robotics, 2009.
